Multi-outlet duplex receptacle system for master switch control



Oct. 3, 1961 R. JOHNSON ETAL 3,003,132

MULTI OUTLET DUPLEX RECEPTACLE SYSTEM FOR.

MASTER SWITCH CONTROL Filed Jan. 6,1959

AT TORNEYS 3,003,132 MULTI-OUTLET DUPLEX RECEPTACLE SYSTEM FOR MASTER SWITCH CONTROL Robert Johnson, Edgeworth, and Thomas E. Hoskins, Coraopolis, Pit, assignors, by mesne assignments, to H. K. Porter Company, Inc., Pittsburgh, Pa., a corporation of Delaware Filed Jan. 6, 1959, Ser. No. 785,236 6 Claims. (Cl. 339-23) This invention relates to mul-ti-outlet electrical systems such as are used along a baseboard of a room or along the back of a bench in a shop or laboratory.

It is an object of the invention to provide an improved multi-outlet electrical system in which some of the outlets are supplied with power continuously and others of the outlets have their power supply controlled by a switch. One feature of the invention relates to a receptacle construction in which two pairs of outlet openings are provided, one pair being connected with the continuously hot circuit and the other with the switch-controlled circuit.

One of the advantages of this invention, as compared with systems where alternate receptacles are switch-controlled, is that it is not necessary to mark the alternate outlets as to which is switch-controlled and which is not, nor is it necessary for a person using the outlets to determine whether he is plugging into an even or odd outlet. With this invention, every receptacle provides the user with a choice of circuits. It is merely necessary to remember that the continuously hot circuit connects with either the right or the left-hand side of the receptacle, as the case may be.

Another object of the invention is to provide a multioutlet electrical system having two diiferent circuits connecting with each receptacle, and with the receptacles constructed so as to receive three wires without increasing the size of the receptacles over conventional one-circuit systems. This permits interchangeability of parts and reduces the cost of the invention besides making it possible to convert a single-circuit system into a twocircuit system.

Another object of the invention is to provide a multioutlet electrical system of the character indicated with the receptacles constructed so that identical conductor elements can be used within the receptacles for connecting outlet openings at the same level with wires located at dilferent levels. The invention provides conductors which can be merely turned around in order to connect with a higher or lower wire. 7

Other features of the invention relate to a construction for making the system more economical to manufacture and more convenient to assemble.

Other objects, features and advantages of the invention will appear or be pointed out as the description proceeds.

In the drawing, forming a part hereof, in which like reference characters indicate corresponding parts in all the views;

FIGURE 1 is a fragmentary front elevation, partly diagrammatic, showing a multi-outlet electrical system embodying this invention;

FIGURE 2 is an enlarged front view of a portion of the system shown in FIGURE 1;

FIGURE 3 is a sectional view taken on the line 3.3 of FIGURE 2;

FIGURES 4 and 5 are enlarged sectional views taken on the lines 44 and 55, respectively, of FIGURE 2;

FIGURE 6 is an enlarged detail view of a conductor which is to be connected with the second or third wire in the receptacle shown in FIGURES 4 and 5;

hired States Patent 0'' 3,003,132 Patented Oct. 3, 1961 ing the conductor for connecting with the first wire in the receptacles; and

FIGURES 8 and 9 are detail views, on a reduced scale, showing the way in which the wires are'connected with the conductors of the receptacles.

The multi-outlet electrical system of this invention includes a housing 15 having a front cover 16 which closes a longitudinally extending opening in the front wall of the housing. There are receptacles 1-8 at spaced locations along the housing 15 and these receptacles are exposed through openings 20 in the front cover '16.

The structure of the housing 15 is best shown in FIG- URE 3. The front cover 16 has a bottom edge which fits into a fold 22 formed in a lower portion of a front wall 24 of the housing. The upper portion of the front wall 24 is made with a bead 26 along the top edge of the opening which is closed by the cover 16. This bead 26 engages a corrugation 28 of an in-turned lip at the top of the cover 16 to hold the cover in its closed position.

The housing 15 has a top wall 30 and a back wall 32.

i The inwardly projecting edge of the housing which forms FIGURE 7 is a view, similar to FIGURE 6, but show the bead 26, provides a channel of which the top wall 30'serves as one side. This channel faces the back wall 32. A receptacle 36 is made in two parts, including a forward part 38 and a rearward part 39. The rearward part extends upwardly above the forward part and has an extension or hook 42, at its upper end, in position to fit into the channel between the top wall 30 and the bead 26.

The receptacle 36 is inserted into the housing 15 before the front cover 16 is assembled with the housing. As the receptacle 36 is introduced into the housing, it is oriented so that the hook 42. passes upwardly behind the inner end of the head 26. The receptacle 36 is then rocked clockwise, in FIGURE 3, to bring the back of the receptacle against the'back wall 32 of the housing 15; and this rocking movement carries the hook 42 further forward in the channel to obtain the assembled relation shown in FIGURE 3.

After the various receptacles 36 have been placed in the housing 15, the front cover 16 is engaged at its lower end with the fold 22, and the front cover 16 is then swung counter-clockwise to snap the corrugation 28 over the head 26. There is an opening 20 for each of the receptacles 36. If any of the receptacles do not register exactly with the openings 20, the hook 42 leaves the receptacles unrestrained in the direction of the length of the housing and some minor shifting of the positions of the receptacles can be made to obtain exact registry with the openings 20.

Each of the receptacles 36 extends for a short distance out from the front cover 16, but there is a shoulder 44 on the front part of each receptacle in contact with the back of the front cover 16 for holding the receptacle against the back wall 32 of the housing.

The front of each receptacle 36 has two pairs of openings for receiving the prongs of a drop cord. These openings include an upper right-hand opening 51 (FIG- URE 2) and a lower right-hand opening 52. The openings 51 and 52 provide a pair of openings. spaced to receive the two prongs of a drop cord fitting. The other pair of openings in the front of the receptacleincludes an upper left-hand opening 53 and a lower left-hand opening 54. As in the case of the first pair of openings 51 and 52, these latter openings 53 and 54 are spaced to receive the prongs of a drop cord fitting; and in the illustrated construction, the top openings 51 and 53 are at the same level, and the lower opening 52 is at the same level as the lower opening 54-. This construction provides a more attractive appearance for the receptacle and also obtains a more compact construction.

Within the housing 15 there are wires for connecting the receptacles with electric power. These wires include a first wire 57, a second wire 58, and a third wire 59. The first wire 57 is preferably the ground wire for the system and either of the wires 58 and 59 can be connected with a continuous source of voltage.

In the circuit connections shown in FIGURE 1, the second wire 58 is connected to the continuous voltage supply and the third wire 59 is connected with the power source through a switch 61.

The wires 57, 58 and 59 are preferably parallel and located at different levels within the housing 15. There are passages through the receptacles 36 for the wires 57, 58 and 59. These passages are preferably channels 64 (FIGURE formed in the back of the front part 38 of each receptacle. The channels can be equally spaced, or at substantially equal spacing from one another, and the wires are preferably in the same plane so as to obtain a compact construction which does not require any increase in the fore-and-aft dimensions of the housing 15. The rearward part 39 of the receptacle covers the channels 64 to complete the passages for the wires. Fastening means, such as screws 66, connect the forward and rearward parts 38 and 39, respectively, together.

At locations behind the openings 51-54, where a connection is to be made to one of the wires 57-59, the passages for the wires are made of increased width and depth, thus providing chambers 71 and 72 (FIGURE 4) and 73 (FIGURE 3).

These chambers 71, 72 and 73 are enlarged portions of the passages for the Wires 57, 58 and 59, respectively. The chamber 71 is long enough to extend behind both of the openings 51 and 52 (FIGURE 2) and there are two conductors 75 (FIGURE 8) attached to the wire 57 in position to register with the openings 51 and 53 (FIG- URE 2). Each of these conductors 75 is confined within the chamber 71, as shown in FIGURE 4, in position to be engaged by the prong of a drop cord inserted through the opening 51, or the opening 53.

The conductor 75 is shown in detail in FIGURE 7. It is preferably made of a single piece of resilient metal, such as Phosphor bronze, or other good conductor, having spring resilience. The conductor 75 has a curved portion 78 extending around an arc greater than 180 and for the purpose of clipping over the wire 57. The conductor 75 has one end 79 which extends beyond the curved portion 78. On the other side of the curved portion 78, the conductor 75 has a fold 80 and an end portion 81, providing a flaring entrance into the fold for receiving the prong of a drop cord fitting.

In its original condition, as shown in FIGURE 7, the end 79 extends beyond a plane 83 which is parallel to the sides of the fold 80. When the conductor 75 is inserted into the chamber 71, the end portion 81 is pressed back by a horizontal wall of the chamber 71, and both the end portion 79 and curved portion 78 contact with the same horizontal wall of the chamber 71. This wraps the curved portion 78 more tightly around the wire 57 and causes the conductor 75 to grip the wire more tightly. The opposite sides of the fold 30 are pressed together to insure a good contact with the drop cord prong that comes between them, and to provide a reaction force for holding the conductor securely clipped on the wire 57.

The chamber 72 is shorter than the chamber 71 and extends behind only one of the lower openings in the receptacle. In the illustrated construction, the chamber 72 is behind the opening 52, and the chamber 73 (FIG- URE 3) is behind the opening 54 only.

There is a contact or conductor 85 in the chamber 72. This conductor is of the same general construction as the conductor 75 and has its corresponding parts indicated by the same reference characters as used for the conductor 75, but with a prime appended. The conductor 85, however, has a somewhat different contour which is provided to increase its width. The conductor 75 snaps over the wire 58 and extends down far enough to locate its fold behind the opening 52.

Within the chamber 73 (FIGURE 3), there is a contact or conductor which is similar in all respects to the conductor 85 already described except for its orientation in the chamber. Since the conductor 85 in the chamber 73 is clipped over the third wire 59, the conductor 85 must be turned upside-down, as compared to the conductor in the chamber 72 (FIGURE 4), in order to locate its fold behind the opening 54 of the receptacle.

FIGURE 9 shows the wire 58 connected with contact or conductors 85 at locations for inclusion in successive receptacles along the multi-outlet system. The wire 58 has its insulation 88 removed along sections of the wire which are equal in length to the portion of the receptacle behind the openings 52 and 54 (FIGURE 2). Thus, all of the wires 57, 58 and 59 have bare sections of the same length at each receptacle. This facilitates manufacturing. It will be understood that the conductors 85 (FIGURE 9) are clipped over the bare sections of wire near the right-hand ends of each section, as shown in FIGURE 9, and that in the case of the third wire 59 (FIGURE 2), the conductor is clipped over the bare section of the wire near the left-hand end.

The preferred construction of the invention has been illustrated and described. Terms of orientation are, of course, relative. Changes and modifications can be made and some features can be used in different combinations without departing from the invention as defined in the claims.

What is claimed is:

1. A receptacle for a multi-outlet electrical system, said receptacle having separate and vertically spaced parallel passages therethrough and lengthwise thereof for difierent wires, a front face on the receptacle having two pairs of openings, each pair including an upper and a lower opening and the pairs being spaced from one another in the direction of the length of the receptacle, but having corresponding openings of each pair at the same vertical level, a first of the wire passages being of such a height that corresponding openings of both pairs communicate with said first passage, a second of said passages being of greater height behind one of the openings than the other and having an opening of only one pair communicating therewith, a third of said passages being of greater height behind one opening than the other and having an opening of only one pair communicating with it, and a difierent opening from that which communicates with the second passage, and contacts in all of the passages behind the openings with portions of each contact in position to connect with a wire extending through the passage but out of line with the openings, the contact in the greater-height portion of the second passage having its wire connecting portion above its associated opening and the contact in the greater-height portion in the third passage having its wire-connecting portion below its associated opening.

2. The receptacle described in claim 1 and in which the receptacle is made in two parts, including a forward part and a rearward part and the passages for the wires are channels located in one of said parts and covered by the other part, and the contacts are resilient metal elements held in the passages by the confronting faces of the forward and rearward parts of the receptacle.

3. The receptacle described in claim 2 and in which the contact elements are spring clips that engage and grip the wires and that are compressed by the confronting faces of the forward and rearward parts of the receptacle to cause the clips to grip the Wire tighter when the parts of the receptacle are brought together.

4. The receptacle described in claim 2 and in which each of the contact elements consists of a single piece of resilient metal having one end portion which bears against a horizontal wall of the passage, an intermediate curved portion having an arc in excess of 180 and within which a Wire is gripped, the curved portion being in position to contact a front wall of the passage, and each contact extends rearwardly from its curved portion to a fold which abuts against the back wall of a passage, and the fold has a forwardly projecting side which terminates at the other end of the contact and in position to abut against a corner where the front wall of the passage meets a horizontal wall of the passage, the fold of each contact being located behind one of the openings through the face of the receptacle and in position to engage a prong of a drop cord fitting inserted through said opening in the front of the receptacle.

5. The receptacle described in claim 1 and in which each contact is a one-piece resilient strip having a curved portion which clips over a Wire and having a folded portion with its fold at the rearward end of its wire passage and located behind an opening through the receptacle for 20 housing, and the contacts for the second and third passages being substantially wider than the contact that connects with the wire in the first passage.

6. The receptacle described in claim 2 and in which one of the parts has an upper portion extending forwardly, above the channels and above said front face, and forming a hook for engaging a channel portion of a front wall of a duct for hanging the receptacle in the duct at a fixed distance from a successive receptacle.

References Cited in the file of this patent UNITED STATES PATENTS 2,267,080 Clayton Dec. 23, 1941 2,351,631 OBrien June 20, 1944 2,700,752 Cataldo Ian. 25, 1955 2,743,423 Parks Apr. 24, 1956 2,939,101 Johnson May 31, 1960 FOREIGN PATENTS 559,266 Great Britain Feb. 11, 1944 

